A semiconductor light-emitting diode (LED) comprises: a substrate; a light emitting structure; and a pair of electrodes for powering the diode. Light Emitting Diodes which are based on Gallium Nitride compounds generally comprise: a transparent, insulating substrate, e.g. a sapphire substrate. With an insulating substrate, both electrodes must be connected from the front of the LED to layers of the light emitting structure.
It is common practice to utilize a Ni/Au contact layer between the window layers formed on the light emitting structure and a thick Au bond pad. This arrangement exhibits limited adhesion; and the contact layer tends to peel during wire bonding to the Au bond pad.
The magnitude of the light emitted by an LED depends on: (a) The percent of the light emitting region that is activated by current flowing between the electrodes; (b) The efficiency of the window structure; and (c) The internal losses of generated light.